1. Field of the Invention
The present invention relates to an electronic component embedded printed circuit board and a method for manufacturing the same.
2. Description of the Related Art
As the size of substrates is limited and multiple functions of electronic devices are required with the miniaturization and thinning of the IT electronic devices including mobile phones, it is required to mount electronic components for implementing more functions in the limited area of the substrate.
However, as the size of the substrate is limited, since it is not possible to secure a sufficient mounting area of the electronic components, there is a demand for a technology of inserting electronic components like active devices, such as ICs and semiconductor chips, and passive devices in a substrate. In recent times, a technology of embedding active devices and passive devices in the same layer or a technology of embedding active devices and passive devices in a substrate by stacking them has been developed.
Typically, a method for manufacturing an electronic component embedded printed circuit board forms a cavity in a core of a substrate and inserts electronic components such as various devices, ICs, and semiconductor chips in the cavity. After that, a resin material such as prepreg is applied inside the cavity and on the core in which the electronic component is inserted to form an insulating layer as well as to fix the electronic component, and a via hole or a through hole is formed in the insulating layer and a circuit is formed by plating to allow the electronic component to conduct with the outside of the substrate.
At this time, a circuit pattern is formed inside and on the via hole or the through hole by plating to be used as an electrical connection means with the electronic component embedded in the substrate, and a multilayer printed circuit board in which the electronic component is embedded can be manufactured by sequentially laminating the insulating layer on upper and lower surfaces of the substrate.
In the conventional electronic component embedded printed circuit board like this, since soldering and reflow processes are repeated in every manufacturing process, a high temperature heat is applied to the laminate, and warpage of the substrate may occur whenever heating the laminate at high temperature. At this time, as the electronic component embedded in the substrate is made of a material having a different coefficient of thermal expansion (CTE) from the insulating layer bonded to the outside thereof, stress is concentrated on the bonding interface with the insulating layer due to repetition of the warpage of the substrate in every heating process, and as the process proceeds, delamination or lifting of the bonding interface occurs due to thermal shock.